1. Field of the Invention
The present invention relates to a user preference information data structure and a method for providing whole or partial multi-media content using the user preference information data structure, and more particularly, to a user preference information data structure which is capable of classifying and setting user's preference information regarding multimedia contents with multiple items to thereby provide users with user request-based whole or partial multi-media information, and a method for providing multi-media information by using the user preference information data structure.
2. Description of the Background Art
Recently, as a digital video technique and an image/video recognition technique are developed, information users can easily search video contents or specific segments of the video content as desired.
That is, users easily understand the whole content of a video stream within a short time by searching only a summary version generated according to user's desire, rather than viewing the whole content recorded in the video stream.
For this purpose, researches are being conducted for searching information desired by the user more easily, for which a content-based information is described to the whole or the partial segments of the multi-media stream so that the user can easily search desired information using the content-based data.
The content-based data may include a producer, a director, an actor in the whole multi-media stream or may include information related to appearance or disappearance of things in a video scene, information on when things happen, interval information of the stream such as a relationship between a character and happenings.
Accordingly, when the content-based data is described for the multi-media stream, the user may select a desired multi-media stream, or easily search only a desired portion (or a segment) of the multimedia stream.
The method using the content-based data will now be described.
In order to satisfy the user's request that “show me only the scene in which a main actor is close up in the movie Titanic”, the video browsing system can display only the desired scene to the user on the basis of the previously described content-based data regarding the multimedia content.
U.S. Pat. No. 5,913,013 discloses a method in which a level is set for a violent scene, a nude scene or a portion of appearance of an actor in a multi-media stream and a code is given for segments, to thereby construct a content map. With this method, the user can easily search a desired portion on the basis of the content map.
However, the method for providing multi-media contents or parts of contents using the content map has a problem that whenever the user wants his or her desired information, the searching condition should be described by the user.
In order to solve the problem, most systems adopts a method that automatically recommend programs or segments of programs by combining a content map with a use user preference information.
As shown in FIG. 5, user preference information may be stored in a non-volatile memory 501 of a terminal device 500 of the user or a server or in a portable non-volatile memory such as a smart card. The user preference information can be automatically learned from the usage history of the user.
In this manner, on the basis of the usage history user preference information can be updated or the user can directly edit his or her user preference information to obtain his or her desired information automatically, thereby expressing a user preference/non-preference.
The user preference/non-preference includes a genre of information such as a melodrama, an action movie, a horror movie, politics, news, economic news, soccer, etc, or general information items related to multi-media content such as producer(s), production date, director(s), characters, a degree of special effects, etc.
The user conventional preference information data structure may indicate preference or non-preference for each item (i.e., a genre of information, a producer, a production date or a director, etc.), and as shown in FIG. 1, it is general to have a preference level (or a value) for each item.
The conventional user preference information data structure can be represented as follows
Pref={(I,v): I denotes a preference item                v is user's preference value related to item I}        
FIG. 1 is a table expressing user preference information in accordance with a conventional art, in which preference/non-preference level is differently set for a single item field (i.e., each director, each genre or each actor, etc.) and each item.
FIG. 2 illustrates a construction of a user preference information data structure in accordance with a conventional art. The user preference information 100 includes a plurality (0, 1, . . . , n) of item user preference information 110. The sub-tree of the user preference information 110 includes a preference item identifier 111 for searching multi-media information or a partial portion of the multi-media information and an item preference/non-preference level 112.
The item user preference information 110 may be formed by items of a similar category, for example, a group (or a set) of preference items by genres or actors. The group (or the set) may be designed to have one-dimensional structure or a hierarchical structure.
The preference item identifier 111 includes items such as a producer, a director or an actor of the multi-media information. The item preference/non-preference level (or a value) 112 indicates the degree of preference for the preference items.
In this manner, the method recommends or provides a multi-media stream or a portion of the multi-media stream (a segment or a still image) fitting the user's taste by automatically filtering multi-media stream or its segment according to the user's preference.
However, generally, as a data format in very diverse types, and further, the content of the multi-media information also includes various genres, there are great number of items to describe the user preference information.
Accordingly, the conventional user preference information data structure formed merely with the single item and a corresponding user preference/non-preference level. But, multi-media information providing method by using the data structure of the conventional art is unsatisfactory in the aspect that since the information desired by the user is expressed merely by the single item and its corresponding preference item level, it can not fully express the user preference.
For example, in case where the user has a high preference level for each of preference item ‘A’ and ‘B’ while he or she does not prefer the content that ‘A’ and ‘B’ appear together at the same time, the user preference expressing method for the single item in accordance with the conventional art fails to fully express the user preference.